Publishing systems comprising a screen, inputting means for inputting text and commands and a processing unit for editing documents are generally well known. Of general interest are "Providing Three Kinds of Attributes For Object Data and Properties", IBM Technical Disclosure Bulletin, Vol. 27, No. 10B Mar. 1985; C. Simonyi, Generic Coding In An Interactive Editor, Digest, Compcon 84, Feb. 27-Mar. 1, 1984, IEEE Computer Society Press (p. 99-103) and Gutknecht, Concepts Of The Text Editor LARA, communications of the Assoc. of Computing Machinery, Vol. 28, No. 9, Sept. 1985 (pages 942-960).
Typically, a document consists of one or more components characterized by a name and by properties. The properties normally have an adjustable value. For example, local values of the properties are applicable to individual components and global values of the properties are applicable to a component type (i.e., all individual components having a specific name), except for those individual components belonging to that component type for which different local values of the properties have been set. The processing unit comprises management means for managing, displaying on command on the screen and changing the value of the properties on command.
One such system that is commercially available is in the form of a computer and a software package known as the "Workstation Publishing System" by Interleaf, Inc., Cambridge, Mass., U.S.A., and is described, for example in "Is What You See Enough To Get?" by R. A. Morris (in: PROTEXT II: Proceedings of the Second International conference on Text Processing systems, Dublin, 1985, ISBN 0 906783 50X). In this system, the inputting means comprise a keyboard and a mouse. The mouse can be used by the operator to select a position on the screen, and commands or text can be inputted at that location by using the keyboard. This system also uses menus which appear locally on the screen after activation by the mouse. The menu comprises a set of commands which can be selected and executed by activation of the mouse.
A system such as that described above enables the operator to make up a document consisting of different components, such as headings, text blocks, footnotes, etc. This document is displayed on the screen in a text window provided with a margin. A label with the name of that component is provided in that margin at the start of each component.
The external characteristics of each component, such as type face and size, margin positions, typographical functions, and so on, are fixed in the properties which may have a different setting or value for each component. The set of properties of a component may be displayed on the screen in a separate window by bringing it up via a menu with the mouse at the label of that component. This window also displays the values of the properties. These can be changed by the operator. If the operator does not change them, then the values preprogrammed or default values apply. The default value can be provided by the supplier of the system or at initialization/installation.
To increase legibility, the operator will often wish to make the appearance of certain components different, e.g., by printing the heading in bold and centered on the line. This can be achieved by giving the properties of that component a corresponding value.
In the above described system, there is one basic component from which the operator can form a number of different components by giving one or more of the properties a different value. In that way the operator can define a number of components tailored to different applications in the document by means of properties which have different values from one another. By giving these components different names (the name of a component is also a property), they can be made distinguishable. A component specialized in this way can then be used at different places in a document.
At the operator's choice, a change of the value of properties of a component can be made to apply to all the components with the same name as the amended component (global change), or be applied solely to the changed component (local change).
As a result, a distinction can be made between two kinds of values of properties: the "global" value which applies generally to all components with the same name (together forming the "(component) type" of that name), and the "local" value which replaces a global value after a local change to an individual component.
In a document it is possible to make new components of an existing type by creation operations and by copying operations. In the case of a creation operation, the system makes a new component whose properties have the global values of the component type whose name has been specified by the operator. In the case of a copying action, the new component is given the same name and local property values, as a component indicated in the document by the operator using the mouse.
In the system described, if the operator changes the global value of a property of a specific component type (i.e., the properties of the first component of that type occurring in the document in the known system), the appearance of the other components of that type remains unchanged because the system locally sets the properties thereof directly to the value prior to the change. This may result in a confusing situation, since it will regularly happen that the local value of a specific property is the same for almost all of the components, but differs from the global value. In the case of a creation operation the operator will think that the component he is obtaining will have the same appearance as (practically) all the other components of the specified type, but the new component supplied by the system has the global property values and hence differs from the expected value.
Although the known system offers the opportunity of adapting both the local properties of all the components of a specific type and the global properties of that type simultaneously through a global change this may overshoot the target, because some of the local changes probably have been made to distinguish a specific component from the other ones and this step is also deleted by a global change.
Accordingly, it is an object of the present invention to provide a system such as those described above that gives the operator a better idea of the consequences of operations on the appearance of document components.